we are ratio as
[tex]=\frac{3}{7}[/tex]
It will be equivalent to only those terms which would be multiple of this term
so, we will multiply top and bottom term by 5
and we get
[tex]=\frac{3\times 5}{7\times 5}[/tex]
[tex]=\frac{15}{7\times 5}[/tex]
[tex]=\frac{15}{35}[/tex]
so, it is very similar to 12/35
so, it will be equivalent to 12/35
so, option-C.......Answer